A Spring Boot microservice responsible for inventory management in the event-driven order platform. It participates in distributed sagas as a Kafka consumer/producer, reserving stock as part of the order fulfillment flow coordinated by the Saga Orchestrator.

Kafka and PostgreSQL must be running before starting the service. Start them via Docker Compose from the shared infrastructure:

cd ~/Workspace/event-driven-simulator/infrastructure/docker-compose
docker compose up -d

This provides:

• Kafka (KRaft mode) — external: localhost:9094, inter-container: kafka:9092
• PostgreSQL — localhost:5432, database: inventory_db

mvn spring-boot:run

The service will be available at http://localhost:8082.

curl -X POST http://localhost:8082/api/v1/inventory/ \
  -H "Content-Type: application/json" \
  -d '{"productId": "prod-123", "availableQuantity": 100}'

curl http://localhost:8082/api/v1/inventory/prod-123

1. Saga Orchestrator publishes a ReserveInventoryCommand to order.inventory.reserve
2. This service looks up the item by productId
3. If found and stock is sufficient → decrements quantity, publishes InventoryReservedEvent
4. Otherwise → publishes InventoryReservationFailedEvent with reason:
   • "Product not found"
   • "Insufficient stock"

mvn test                          # Run all tests
mvn test -Dtest=ClassName         # Run a single test class
mvn spotless:apply                # Auto-format (Google Java Format)
mvn spotless:check                # Verify formatting
mvn clean install                 # Full build

Before committing:

1. mvn spotless:apply
2. mvn spotless:check
3. mvn test

src/main/java/com/platform/inventoryservice/
├── config/           Kafka consumer and producer configuration
├── controller/       REST endpoints
├── service/          Reservation business logic
├── model/            InventoryItem JPA entity
├── repository/       Spring Data JPA repository
├── messaging/
│   ├── consumer/     Kafka listener for ReserveInventoryCommand
│   └── producer/     Kafka publisher for result events
├── event/
│   ├── inbound/      ReserveInventoryCommand DTO
│   └── outbound/     InventoryReservedEvent, InventoryReservationFailedEvent DTOs
└── exception/        InventoryItemNotFoundException, GlobalExceptionHandler